Treatment of resin oils



Pian s Apr. 11, 1944 UNITED- STATES PATENT- OFFICE auauc Edwin Louis cure, Philadelphia, m...

by memo assignments, to Allied assignor, Chemical &

Dye Corporation, a corporation or New York No Drawing. Application January 14, 1941,

' Serial No. 874,899

\ scams. (or. zoo-2s)" resin which may contain in addition to polymerized coumarone and indene a substantial proportion of the polymers of other resin-forming compounds such as styrene and its homologs present in coumaroneand indene-containing oils.

In the commercial production of paracoumarone resin, oil fractions such as crude solvent naphtha containing resin-forming polymerizable constituents, chiefly coumarone and indene, are treated with a suitable polymerization catalyst, usually an acid catalyst such as concentrated sul- {uric acid. The acid sludge is separated from the oil, the acid remaining in the oil is neutralized with an aqueous alkaline solution such as caustic soda orsoda ash solution, and the neutralizedoil is then distilled to obtain refined oil as distillate and paracoumarone resin as still residue. As is well known in the paracoumarone resinart. the resin frequently darkens and develops objectionable odor during manufacture. especially during polymerization and distillation to separate the resin from the solvent medium. For many purposes. e. g. in the manufacture of varnishes, light colored resins'iree from objectionable odor are highly desirable and much research has been devoted to improving the quality of acid-polymerized paracoumarone resin. For example, Miller Patent No. 1,360,665 oi November '30, 1920, discloses the maintenance of v the temperature oi. the solvent naphtha below constituents of resin oil with an acid-type catalyst such as stannic chloride or boron trifluoride or sulfuric acid, preferably concentrated suliuric acid, are heated in the presence of an alkali or alkaline earth metal or magnesium or zinc salt of a' carboxylic acid during or prior to distillation of the resinsolution to recover the resin therefrom. Preferably alkali or alkaline earth metal salts of carboxylic acids oi sufflciently high molecular weight to render the salts at. least slightly soluble (i. e. at leastone part per ten thousand parts of resin oil) in the resin-containing oils are utilized; such salts of carboxylic acids having a molecular weight of at least sixty have been found suitable tor the practice of this invention. The expression "resin oil" is used herein to refer to the oils recovered from coke oven tar and water gas tar by distillation, oils obtained in the production of coke oven and water gas, and oildistillates including drip oils obtained irom oils collecting in manufactured gas distribution and storage systems, and oils obtained in the cracking and reforming of petroleum, which oils contain a varying but substantial content of unsaturated resin-forming constituents. such as coumarone and indene, polymerizable by acid catalysts, such as sulfuric acid. to produce resins.

I have found that heating resin oils 'coutaining acid-polymerized resin in the presence of alhall or alkaline earth metal or magnesium or zinc salts of carhoxylic acids during o-r,'prior to distillation greatly reduces the tendency oi the resin to darken and develop objectionable odors about C. during polymerization to improve 7 n the colonel the resin; frequently, however, the resin darkens while the resin-containing oil are being? distilled notwithstanding suchtemperature during distillation and hence markedly improves the quality and value of the resin obtained. While the reason for the improvement in the character of the resin is not fully understood, one possible explanation is that one or more compounds which are stable at the temperatures prevailingdurine polymerization but are unstable at the distillation temperatures are iormed during polymerization and decompose during distillation to produce products which contaminate the resin and im In accordance with'the invention, resin. solu-'- tions produced by polymerizing the resin-forming part poor color and odor thereto. The salts of the carhoxylic acids employed in accordance with the invention are believed to neutralize or otherwise obviate the cblectionabl characteristics oi these thermal decomposition products.

" The invention may be carried into eflfect, for

example, by subjecting a resin oil such as crude solvent naphtha boiling within the range of from 135". .to 210 C. or fractions from it boiling e. g.

from 135? to 155 C., or from 165 to 185 C., etc.,

and containing from to 80 per cent of resinforming polymerizable constituents, chiefly cou- .marone and indene, to the action of an acid polymerization catalyst such as concentrated sulfuric acid, separating the acid sludge from the oil,

neutralizing the acid remaining in the oil by washing it with an aqueous solution of soda ash with a solution of, the desired vase in a small amount or water. In some cases distillation of the resin-containing oil in the presence of the amount of reagent necessary to obtain the desired effect results in resin containing more ash, e. g. inorganic sulfates, than. is desirable for some purposes. In such cases the resin-containing oil may be heated to a temperature of from 150 to 210 C. in the presence of the salt of the carboxylic acid, e. g. under refluxing conditions or in a closed vessel, and the inorganic sulfate formed separated from the oil by permitting it to set-.

tle or washing the oil with water. The resincontaining oil may then be distilled for the recovery of 'the resin in the customary manner. If the carboxylic acid is of volatile character it will be removed from the resin during distillation of the oil, or the acid may be removedby incoraasasie agents and observing the minimum amount of -reagent that produces resin of satisfactory color and odor.

The following examples are illustrative of the invention.

Example I An oil of coke oven origin boiling at from about 160 to 200 C. and containing about 30 per cent by weight of polymerizable constituents, chiefly coumarone and indene, was polymerized using concentrated (66 B.) sulfuric acid as catalyst, the acid sludge was drawn oil, the polymerized oil neutralized with aqueous soda ash solution and then washed with water. The resincontaining oil was then heated to 80 C. and .88 per cent by weight of powdered (100 mesh) calcium resinate was dissolved therein. The oil was then distilled to vobtain paracoumarone resin as still residue and refined oil as distillate. The resin which was of about 135 C. melting point vhad a mild and pleasant odor and a color of 0-1 as measured on the customary resin scale of color described more fully hereinbelow.

Example I:

An oil of coke oven'orlgin boiling at from about 160 to 200 C. and containing about 30 per cent by weight of polymerizable constituents, chiefly coumarone and indene, was polymerized using concentrated sulfuric acid as catalyst, the acid sludge was drawn oil, the polymerized oil neu-' tralized'with aqueous soda ash solution and then washed with water. The resin-containing oil was then heated to 80 C. and .6 per cent by porating a small amount of alkali in the wash- As hereinabove indicated, alkali or alkaline earth metal or magnesium or zinc salts of sufficiently high molecular weight carboxylic acids to render the salts at least slightly soluble in the resin-containing oils are the preferred reagents employed in carrying out the invention. The pre-; ferred reagents include the alkali and alkaline earth metal salts of carboxylic acids derived from vegetable and animal oils and rosin,such as the laurates, stearates and resinates' of sodium, potassium, calcium and other alkali and alkaline earth metals. The corresponding zinc or magnesium salts may also be utilized. The acetates, oxalates, benzoates, phthalates and other carboxylic acid salts of alkali and alkaline earth metals and magnesium and zinc'also improve the color and odor of the resin obtained. The amount of reagent necessary to'obtain resin of optimum color and odor depends on many factors, such as the proportion of resinin the resin-containing weight of calcium laurate, based on the weight 01 the, oil was dissolved therein. The oil was.

.then distilled to obtain paracoumarone resin as still residue and refined oil as distillate. The resin was of about 135 C. melting point, had a mild and. pleasant odor and a color of (3-1 as measured on the customary resin color scale.

Example II An oil of coke oven origin boiling at from about 160 to 200 C. and containing about 30 per cent by weight of polymerizable constituents, chiefly coumarone and indene, was polymerized with concentrated sulfuric acid catalyst, the' acid pleasant odor and .a color of 0-2.

oil, the extent to which the resin tends o darken.

and develop objectionable odor during distillation, and the particular reagent utilized. In general from 0.05 to 2.0 per cent of the reagent based on the weight of the resin-containing oil is sufficient to inhibit darkening of the resin and development oi. objectionable odor during distillaor 33.5 per cent hydrochloric acidand 1580 cc.

- 450 grams of c. P. ferric chloride (r'ecnsmo),

tion. The optimum amount of reagent for each The invention results in marked improvement in the character of resins recovered from ofls containing resins that tend to develop objectionable odor and dark color during distillation. Resin color is usuallydesisna ed by a color number on the customary resin scale. This scale is determined by preparing three stock solutions.

namely, stock solution "A" constituted of 40. cc.

of water; stock solution B made by triturating 270 cc. of solution "A and filtering. using the clearfiltrate for stock solution B;" and solution "C" made by trlturating 60 grams 01' C. I P. cobalt chloride (CoClz.6HaO) and cc. of solution "A" and filtering, using the filtrate for stock solution "Cf," and 111131118 t ese stock eolu tions in various proportions to form standard color mixtures corresponding to the respective The solutions should be well color numbers. mixed andabout 25-28 cc.ot each ,0! the. mixtures placed in a 1 oz. test bottle,' each bottle labeled with its color number and the bottle sealed with sealing wax to prevent evaporation or water and hydrochloric acid. The proportions of the stock solutions employed in the mixtures corresponding to representative color numbers are given in the following table:

To determine the color oi a resin a two-gram sample thereof is dissolved in 25 cc. of benzol andthe depth of the color of the resin solution thus produced is compared with the standard colors. If the sample lies between two consecu tive numbers, its color is reported as the higher one. For purposes of comparison there are given below (A) the color numbers of the resins produced in accordance with Examples 1, II and m, and .(B) the color numbers of resins recoveredin the usual manner from portions of the oils utilized in the respective examples, 1. e. by distilling the oils without treatment with a salt of a carboxylic acid:

I II in A. Resin oi Example: Color number -1 0-1 0-2 B. Resin obtained from oil oi examples without treatment with salt of carboxylic acid: Color numbe 0-10 0-10 C-iO Thus'it will be seen the invention renders possible the recovery of light colored resins oi pleasant odor from oils containing resins which heretoiore darkened objectionably and developed unpleasant odors during distillation of the oils. Sincelight colored resin of mild odor is neceswhich comprises heating said on after said polymerlzation is effected in the presence of a salt I present in resin oilcontaining at least one polymer'izable material selected from the group consisting of coumarone and'indene with concentrated sulfuric acid polymerization catalyst, neutralizing the oil and distilling the resin-containing oil in the presence oi! a salt of an organic carboxylic acid and a metal selected from the group consisting of alkali metals, alkaline earth metals, magnesium and zinc.

3. A process for the production 0! acid-polymerized resin of improved character which comprises polymerizing polymerizable materials present in resin oil containing at least one polymerizable' constituent selected from the group consisting of coumarone and indene with suli'uric acid polymerization catalyst, heating the resin-containing oil in the presence or a salt of an organic carboxylic acid'vand a metal selected from the group consisting of alkali metals, alkaline earth metals, magnesium and zinc.

4. In a process of treating oil containing resin produced by polymerizing by acid-type catalyst at least one polymerizable constituent selected from the group consisting of coumarone and indene, which resin tends to deteriorate during recovery from the resin-containing oil, the improvement which comprises heating the resincontaining oil in the presence of a salt of an organic carboxylic acid and a metal of the group sary for many purposes and hence is of greater value than resin of dark color or unpleasant odor, the invention represents a substantial admum: in the commercial production of acidpolymerized resins. 1

Since certain changes may be made in the above without departing from the scope of the invention, it is intended that all matter contained in the above description shall be interpreted as illustrative and not in a limiting sense.

What is claimed is:

1. In a process for the production of resin involving subjecting oil containing at least one polymerizable resin-forming constituent of the group consisting oicoumarone and indene to the action of sulfuric acid polymerization catalyst, neutralizing the oil and distilling the oil to recover the resin therefrom, the improvement magnesium and zinc.

consisting of alkali metals, alkaline earth metals,

5. A process which comprises treating with an acid-type polymerization catalyst oil containing at-least one'polymerlzable resin-forming material selected from the group consisting of coumarone and indene, neutralizing the resultant resin-containing oil, and heating the oil in the presence of a salt of an organic carboxylic acid and a metal selected from the group consisting of alkali metals, alkaline earth metals, magnesium and zinc.

6. In. a. process for the production of paracoumarone resin involving subjecting oil containing paracoumarone resin-forming constituents to the action of concentrated sulfuric acid polymerization catalyst to polymerize said constituents, neutralizing the resin-containing oil, and distilling the resin-containing, oil to recover the resin therefrom, the improvement which comprises heating said oil after neutralization thereof in the presence of an alkaline earth metal salt of an organic carboxylic acid of suilicient v 3 molecular weight to render the salt at 1 least slightly soluble in said oil.

7. In a process for the production of paracoumarone resin involving subjecting oil containing paracoumarone resin-forming constituentsto the action of concentrated sulfuric acid polymerization catalyst to polymerize said constituents, neutralizing the,resin-containing oil, and distilling the resin-containing oil to recover the resin therefrom, the improvement which comprises heating said oil after neutralization thereof in, the presence of an alkah metal salt of an organic carboxylic acid of sufllcient molecular weight to'render the salt at least slightly soluble in said oil.

8. In a process for the production of peracouimprovement which comprises heating said oil mim Mn vol ing subjecting Q11 0011mm! after neutralization thereof in the presence of peracoumar'one resin forming constituents to the a. magnesium salt of an organic carboxylic acid cti n of co centrat d f i a d p lymerizaoi suflicient molecular weight to render the salt tion catalyst w p lymerize said constituents, I at least slightly soluble in said oil. neutralizing the 11, and distilling the resin-con- EDWIN LOUIS CLINE. taming oil to recover the resin therefrom, the 

